Upgraded AHS Wellbeing Through the Joining of Vehicle Control and Correspondence

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Vehicle Dynamics Lab. Research Areas. Tire/street grating estimation ... expect a static model for vehicle 3% blunder contrasting with element vehicle model ...

Presentation Transcript

Slide 1

Improved AHS Safety Through the Integration of Vehicle Control and Communication October 2002 J. K. Hedrick, R. Sengupta, Q. Xu, C. Lee, Y. Kang

Slide 2

Communication engineering Goal = remote system valuable for: 1) Cooperative grinding estimation 2) Cooperative Emergency Maneuver 3) AHS and agreeable versatile journey control Emergency Braking Maneuvers Tire/street rubbing estimation Goal: Develop a sheltered control technique for the crisis braking move of detachments. Objective: Real time estimation of greatest tire-street grinding Research Areas

Slide 3

Communication design Tire/street rubbing estimation Road Condition & Maximum Friction Coeff. Data from different vehicles and street side infra structure. Crisis Braking Maneuvers " SAFETY " Project Goals

Slide 4

Slip-based Road Condition Estimation

Slide 5

Overview and Benefits of the Research Overview Empirical approach Effect-based technique Real Time work Benefits Estimation of max. increasing speed point of confinement of the vehicle. Crisis Braking Control for the Platoon. Street Condition versus Position Map.

Slide 6

Slip/Friction Coefficient Calculation Friction Coefficient Slip Max Acceleration Maximum erosion coefficients decides most extreme speeding up or deceleration

Slide 7

Slip Slope Vs ��  Affecting Factors Road Condition Tire Type Tread Pattern Tread Depth Velocity ��  Focus on Linear Region �� Slip Slope, k

Slide 8

Schematic of the Estimator

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Static Normal Force Observer Normal Force �� friction coefficient figuring �� effective tire span estimation Static typical constrain spectator expect a static model for vehicle�� 3% blunder contrasting with element vehicle show Static Normal Force Model

Slide 10

Effective Tire Radius Observer Tire range is required for Slip Calculation Tire Radius Change is a Function of Normal Force Tire Pressure Velocity

Slide 11

Tractive Force Estimation

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Brake Gain Estimator Brake Gain Change Heat Water Wear of Brake Pad, and so on �� sometimes changes more than half Model : Front Wheel Dynamics Method : Recursive Least Square Method Using Bounded Forgetting

Slide 13

Slip Slope Vs Each vehicle has its own slip slant under same street Dry street condition �� set as Reference slip slant Maximum rubbing coefficient change rate/Slip incline change rate in view of reference slip slant �� Linear Assumption

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Slip Slope and Estimation Example : Wet ��  Dry Slip Slope Estimation Using RLS technique Estimation Based on slip slant

Slide 15

Emergency Braking Maneuvers

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Emergency Braking Controller (Longitudinal Control) Requirements for crisis braking Control power against the high slip condition amongst street and tire. Erosion coefficients estimation calculation. Control technique : Dynamic Surface Control

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Experimental Set-up Experimental Vehicle utilized : Ford red Lincoln town auto Sensors and actuators : wheel speed sensors brake weight sensors 5 th wheel speed sensor brake and throttle actuators Computers with continuous OS : QNX working framework

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Simulation Results Simulation with Dynamic Surface Control (6 m/s 2 deceleration)

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Experimental Results Experiments in same circumstance ( 6 m/s 2 deceleration)

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Analysis of the Result The execution of the Dynamic Surface Controller is sensible (1~2m blunder with –6 m/s 2 ) in a crisis braking circumstance. Control execution relies on upon erosion coefficients.  "Erosion coefficient estimation" is important.

Slide 21

( Emergency Braking Control Strategies for Platoons Emergency braking for the Platoons : Difference of max. deceleration constrain between vehicles can bring about impact. Agreeable Emergency Control. ) Vehicle with Worst Braking Capacity transmits its data.

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Simulation Results Space & speed following [m/s] [m]

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